Solvent dyeing of living human hair



United States Patent US. Cl. 8--10.1 4 Claims ABSTRACT OF THE DISCLOSUREA process for dyeing human hair which comprises contacting the hair witha dyeing composition comprising an aqueous solution, suspension ordispersion of a dye, an organic solvent for the dye, and a dissolvedaromatic compound which is solid at the dyeing temperature and acts toincrease the rate of uptake of the dye by the hair.

This invention relates to dyeing.

It is well known that the dyeing of a wide variety of materials bytreatment with an aqueous solution, dispersion or suspension of a dyecan be improved by including an organic solvent for the dye in theaqueous dyeing composition. 7

Thus, it is known from British patent specification 856,381 to includein the aqueous solution, dispersion or suspension of a dye with whichkeratinous fibers, such as silk and wool, orregenerated protein fibersare to be contacted to effect the dyeing thereof, an organic compoundwhich is a solvent for the dye, and which is a liquid under theconditions of dyeing an insoluble or only slightly soluble in water, thesolubility of the dye in the organic compound being greater than thesolubility of the dye in water. Organic compounds (solvents) which maybe used in the process include: aliphatic alcohols, for example n-butylalcohol and amyl 'alcohol; aromatic hydroxy compounds, for examplebenzyl alcohol; esters, for example amyl lactate; aldehydes; ketones;and aromatic hydrocarbons.

British patent specification 872,506 describes a dyeing process similarto that described in the above specification although in specification872,506 the treatment is applied to leather, skins and/or animal fibersattached thereto. The solvents that can be used are similar to thosethat can be used in the process of specification 856,381.

British patent specifications 826,479 and 918,597 also describe a dyeingprocedure similar to that described in patent specification 856,381,although in specifications 826,479 and 918,597 the process is applied tothe dyeing of human hair. The solvents used in the hair dyeing processof these patents include aliphatic and aralkyl alcohols, for exampleamyl alcohol and benzyl alcohol, and esters, for example amyl lactate.

British patent specification 840,904 describes a dyeing process similarto that described in British patent specification 826,479 although inthis case the organic solvent must be one of a number of specifiedalcohols and it must be miscible with water in the proportion in whichit is present. Alcohols for use in the process described in specification 840,904 include butyl alcohol; aralkanols, for example benzylalcohol; and cycloaliphatic alcohols, for example cyclohexanol.

British patent specification 979,405 discloses the use as solvents ofcertain urea derivatives which are liquid at the dyeing temperature.

Benzyl alcohol as well as other slightly water miscible and .waterimmiscible solvents referred to in the above specifications increase therate of dyeing of the fiber or other material treated. This effect isparticularly useful in the dying of living human hair because it enablesa good uptake of dye to be obtained even at the relatively lowtemperatures that have to be employed for such dyeing.

British patent specification 669,192 which concerns the dyeing of fursand skins also disclosesa dyeing procedure in which an organic solventfor the dye is included in the dyeing composition. In the proceduredescribed in specification 669,192 the solvent employed is a partiallyor completely Water miscible aliphatic low molecular alcohol, ketone orester or mixture thereof. The dyeing composition described contains 10%or more of the solvent. The dyeing can be carried out at relatively lowtemperatures, for example between 20 and C. Examples of the solventsemployed are ethyl alcohol, glycol, acetone and ethyl acetate.

British patent specification 819,184 which relates to the dyeing ofkeratinous fibers, particularly hair, also describes the use of anorganic solvent which is completely miscible with-the water in theproportion in which it is present. In this instance the solvent employedis one having the general formula:

.where R represents a monovalent aliphatic or araliphatic hydrocarbongroup containing not more than 8 carbon atoms and n is from 1 to 4.Examples of these solvents are 2-butoxyethanol and2-[(beta-ethoxy)-ethoxy]-etha- 1101. The use of these solvents increasesthe rate of uptake of the dye on the hair and enables keratinous fibers,e.g. live hair, to be dyed at ambient temperatures.

We have now discovered that the increase in the rate of dye uptake thatresults from the use of solvents as mentioned in the abovespecifications can be further improved by including dissolved in thedyeing composition a wide range of aromatic compounds which are solid atthe dyeing temperature; such a compound will hereinafter be referred toas a solid aromatic compound.

Accordingly, the present invention provides a dyeing composition whichcomprises an aqueous solution, suspension or dispersion of a dye and anorganic solvent for the dye, the composition additionally comprisingdissolved therein a solid aromatic compound so as to improve the rate ofuptake of the dye on the material to be dyed. Dye is used in thisparagraph and hereinafter to include direct dyestuffs, i.e. dyestuffscapable of being fixed directly and in the final shade by the product tobe dyed, without it being necessary to interpose any chemicaltransformation, and water insoluble colored organic compounds.

The invention also provides a process which comprises contacting thematerial to be dyed with a dyeing composition comprising an aqueoussolution, suspension or dispersion of a dye and an organic solvent forthe dye, which solvent is liquid under the conditions of dyeing, thedyeing composition additionally comprising a solid aromatic compoundwhich acts to increase the rate-of uptake ofthe dye by the materialcontacted.

The invention may be applied to the dyeing of the various materialsmentioned in the prior patent specifications referred to. In the case offibers, these can either be in the natural state or Woven or otherwisemade up into fabrics or garments. The invention is particularlyapplicable to the dyeing of keratinous fibers such as hair.

Experiments carried out have indicated that the solid aromatic compoundseffective as increasing the rate of uptake of the dye from dyeingcompositions containing solvents are those containing an aromatic ringand at least one of the following groups as substituents of the ring:carboxylic acid, amide and substituted amide, hydroxyl and estersthereof, nitrile, aldehyde, ketone, halogen, amine, alkoxy, ureido, andaliphatic groups, for example saturated or unsaturated groups containingup to 6 carbon atoms, which aliphatic groups are themselves substitutedby at least one hydroxyl or carboxyl group.

The solid aromatic compound molecule may contain a phenyl or naphthylring.

The classes of compounds from which the solid aromatic compound may bechosen include: carboxylic acids, e.g. benzoic, cinnamic, salicylic,hippuric, and naphthoic acids; monoand polyhydric phenols; and chlorobenzenes.

Examples of compounds containing more than one of the above substituentgroups are o-anisaldehyde, o-amino phenol and p-chloro phenol. Thesubstituent groups may be the same as in, for example, p-dichlorobenzeneand o-dimethoxy benzene.

Examples of compounds containing a substituted aliphatic group aremethoxy phenyl acetic acid, p-nitro benzyl alcohol and cinnamic acid.

The solid aromatic compound may comprise an unsubstituted hydrocarbongroup attached to the aromatic ring. Such a group may be a phenyl groupor an aliphatic group such as an alkyl or alkenyl group having up to 6carbon atoms, for example. Other groups may be present, for examplenitro, nitroso, sulphonic acid or substituted sulphonic acid groups.

Examples of compounds having other substituents present are o-cresol,thymol, sulphanilic acid, rn-nitrobenzaldehyde, p-nitro-benzyl alcohol,sulphanilanilide, pnitrobenzyl alcohol and 2,4-dichloronitrobenzene.

The optimum amount of the solid aromatic compound to be used will tosome extent be dependent on the other components of the dyeingcomposition such as the dye and solvent. In most cases an amount of atleast 0.5% by weight of the dyeing composition will be necessary toproduce a significant increase in the dyeing effect. For the dyeing ofhair usually amounts in the range 1 to give the best results. Amounts ofthe solid aromatic compound in excess of its solubility in the dyeingcomposition are not objectionable but do not give any significantadvantage and usually such an excess will not be used.

As the dyeing of living hair is usually carried out below 45 C. thesolid aromatic compound used in this instance can have a melting pointas low as 45 C., or even lower depending on the actual dyeingtemperature used. Higher temperatures may be used in other dyeingtreatments, for instance in wooldyeing, but then the range of solidaromatic compounds that can be used is smaller. Thus for W001 dyeing oneemploys solid aromatic compounds having a melting point above about 80C. or in any event above the actual dyeing temperature used.

As is known from the abovementioned specifications, a wide variety ofdyes can be used in solvent-containing dye systems and those mentionedcan be employed in performing this invention.

Among the dyes that can be used are reactive dyes which containchromophoric groups linked to a reactive group such as monoordi-chlorotriazine, dior tri-chloropyrimidine or vinyl sulphone. Reactivedyes free from a sulphonic or non-chelated carboxylic acid group such asdescribed in British patent specification 953,230 can also be used.

As examples of dyes which may be employed in carrying out this inventionare mentioned the following- C.I. classification 13390 Acid Blue 9219140 Acid Yellow 23 45190 Acid Violet 9 Solway Purple R 60730 AcidViolet 43 Brilliant Alizarine Milling Blue 61585 Acid Blue 80 CarbolanViolet 2RS 62165 Acid Violet 51 Carbolan Blue HR 62075 Acid Blue 138Premetallized dyes:

Both 1:1 and 2:1 complexes e.g. Neolan Black 2R 15691 Acid Black 43Mordant dyes, e.g.:

Solochrome Black 6RN 14640 Mordant Black 3 Acid Alizarine Black N 15690Mordant Black 15 Solochrome Black F 26695 Mordant Black 5 Disperse dyes,e.g.:

Celliton Blue B 61500 Disperse Blue 14 Celliton Fast Blue FFB 62050Disperse Blue 6 Celliton Blue 36 64505 Disperse Blue 31 Direct dyes,e.g.:

Melanthine BH 22590 Direct Blue 2 Diphenyl Fast Black B 27720 DirectBlack 51 Diphenyl Brilliant Violet BC 27905 Direct Violet 51 Solventdyes, e.g.:

Zapon Fast Violet R 15680 Coomassie Violet 2RS 45190 Solvent Violet 10As will be seen from the above mentioned specifications, a large numberof different solvents are known to be used in dyeing compositions andthose mentioned can be used in carrying out this invention. Among thesolvents which may be used in accordance with the present .inventionare:

aliphatic alcohols, e.g. those containing 1-6 carbon atoms,

including cyclohexanol;

aralkanols, e.g. benzyl alcohol;

alkoxy alcohols e.g. 3-methoxybutanol, ethoxyethanol and methoxyethanol;

aliphatic ketones, e.g. ethyl methyl ketone and methyl isobutyl ketone;higher glycols, e.g. hexylene glycol; aliphatic esters, e.g. amyllactate;

as well as ethanol 2-methoxyacetate, geraniol, Carbitols and digols, andtetraethyl urea. Carbitols are monoethers and monoesters ofdihydroxyethyl ether.

As is known, the more miscible the solvent the greater the proportionthat is to be used.

The dyeing composition may also contain further ingredients known in theart. For instance, in compositions intended for dyeing human hair theremay be included thickeners, surface active agents or aliphatic acids,such as acetic or lactic acid. One may also include where the solvent isnot miscible with water, a liquid miscible with both the water andsolvent.

In a modification of the invention the material to be dyed is contactedsuccessively with an aqueous solution or dispersion of the dye and alsowith a liquid organic solvent for the dye (either the said solution orsolvent being applied first), the solid aromatic compound beingdissolved in either the aqueous solution or in the organic solvent or inboth of them.

In a further modification of the invention the material to be dyed iscontacted successively with a solution of the dye in a liquid organicsolvent for the dye and also with water (either the organic solvent orthe water being applied first), the solid aromatic compound beingdissolved in either the organic solvent or in the water or in both ofthem.

The following examples illustrate the invention. All percentages are byweight.

The dyeing compositions employed in the following examples eachcomprised an organic solvent, a solid aromatic compound (in solution inthe composition), 1% dye, 1% monoethanolamine lauryl sulphate and thebalance water. The pH of the dyeing composition in each case was about4.

The dye in each of Examples 1 to 34 was the acid dye Solway Purple R 125(C.I. 60730 Acid Violet 43).

In Examples 1 to 26 the amount of the solvent was in Examples 27-30, 5%;and in Examples 31-34, In Examples 1 to 9 the concentration of the solidaromatic compound was 2% and in Examples 10-34, 3%.

The solvent and solid aromatic compound used in Examples 1 to 34 are setout in Table I TABLE I Solid aromatic compound Benzolc acid.

Cinnamic acid. Methoxy phenyl-acetic acid. Salicylic acid.

p-Amino benzoic acid.

. Hippuric acid.

. Acetyl salicylic acid.

. Phthalic acid.

. Sulphanilic acid.

Solvent Resorciuol.

Hydroquinone.

. Thymol.

o-Amino phenol. p-Chloro phenol. p-Nitro-benzyl alcohol.

. Phenylurea.

...- m-Nitrobenzaldehyde. o-Anisaldehyde.

24dichloronitro benzene.

Benzyl alcohol- Benzoic acid. ....-do Salicylic acid.

-.. p-Amino benzoic acid.

-. Thymol. Benzoic acid. Salicylic acid. p-Aminobenzoic acid.

In Examples 35 to 40 the composition employed was the same as that inExample 27 except that the dye employed was Coomassie Dark Blue BL (CI.50330 Acid Blue 61) and instead of benzyl alcohol the solvent was as setout in Table 11.

TABLE II Example: Solvent 35 Cyclohexanol. 36 3-methoxybutanol. 37 Ethylmethyl ketone. 38 Hexylene glycol. 39 Ethanol Z-methoxy acetate. 40 2-[(8-ethoxy)-ethoxy]-ethanol.

41 Tetraethyl urea.

In Examples 42 to 52 the composition employed was the same as that inExample 31 except that the dye employed was as indicated in Table HI.

TABLE III Example Name of dye C.I. classification of dye 42 CoomassieBlue R.L 13390 Acid Blue 92. 43. Resorcine Brown 20170 Acid Orange 24.44. Disulphine Blue 42045 Acid Blue 1. 45 Coomassie Voilet; 2R8 45100Acid Violet 9. 46 Nigrosine 50420 Acid Black 2. 47 Neolan Black 2R 15691Acid Black 43. 48.- Solochro'me Black GRN 14640 Mordant Black 3. 49.CellitonBiue B... 61500 Disperse Blue 14. 50- Melan thine BH.-. 22590Direct Blue 2.

Coomassie Violet 212s I 45190 Solvent Violet Switches of human hair weredyed with each of the compositions ofithe above examples by immersingthe switches for 10 minutes in the dyeing compositions at 25 C. Theywere then washed with water and dried. Switches of hair" were alsotreated in a similar manner with the corresponding compositions fromwhich the solid aromatic compound had been omitted. In every case theintensity of the color of the hair was noticeably greater in the case ofdyeings with the compositions set out in the tables than with thosecompositions from which the solid organic compounds had been omitted.

In Examples 53 to 55 materials other than human hair were dyed. Thedyeing composition used in each case consisted of PercentMonoethanolarnine lauryl sulphate 0.3 n-Propanol 15.0 Benzoic acid 3.0Solway Purple R 1.0 Water to 100.0%.

The materials used are indicated in Table IV.

The fibers were dyed by immersing them for 10 minutes in the dyeingcomposition at 25 C. They were then washed with water and dried. Theintensity of color of the dyed fibers was in each case greater than thatobtained using dyeing compositions of the same pH but containing nobenzoic acid or containing in place of the npropanol and benzoic acid,6% of benzyl alcohol.

What is claimed is:

1. A process for dyeing human hair attached to the head which comprisescontacting the hair at a temperature below about 45 C. with an effectiveamount of a dyeing composition comprising an aqueous solution,suspension or dispersion of a direct dye and an organic solvent for thedye which solvent is liquid at the dyeing temperature and is selectedfrom the group consisting of aliphatic alcohols, aralkanols, alkoxyalkanols, aliphatic ketones, hexylene glycol, aliphatic esters,tetraethyl urea and 2-(betaethoxy)-ethoxyethanol, the dyeing compositionadditionally comprising dissolved therein from about 1% to about 5% byweight of the composition of an aromatic compound which compound issolid at the dyeing temperature, acts to increase the rate of uptake ofthe dye by the hair and contains one phenyl or naphthyl ring.

2. A process as claimed in claim 1, in which the organic solvent isbenzyl alcohol.

3. A process as claimed in claim 2, in which the aromatic compound is acarboxylic acid.

4. A process as claimed in claim 3, in which the carboxylic acid isbenzoic acid.

(References on following page) References Cited FOREIGN PATENTS UNITEDSTATES PATENTS 918,597 2/1963 Great Britain. 12/1931 Kern et a1 X1,227,621 3/1960 France. 1,296,934 5/1962 France.

1/1940 Krltchevsky 16788 1 I X 5 70,067 10/1958 France. 2/ 946 Heman(Addition to No. 1,138,955 11/1960 Bashford 1,159,331 2/1958 France.

5/1961 Seemuller 167-88 7/ 1965 Brechner 167-88 ALBERT T. MYERS, PrimaryExaminer 8/1965 Sherburne 10 v. c. CLARKE, Assistant Examiner 9/1965Lecher et a1. 167-88 11/1967 Lerner et a1. 167-88

